JP7738575B2 - Battery cell, battery cell manufacturing method, battery cell manufacturing system, battery, and electric device - Google Patents

Description

The present invention relates to the field of battery technology, and more specifically to battery cells, methods for manufacturing battery cells, systems for manufacturing battery cells, batteries, and electrical devices.

Battery cells are widely used in electronic devices such as mobile phones, laptops, electric bicycles, electric cars, electric airplanes, electric boats, electric toy cars, electric toy boats, electric toy airplanes, and power tools. Battery cells may include nickel-cadmium battery cells, nickel-metal hydride battery cells, lithium-ion battery cells, and secondary alkaline zinc-manganese battery cells.

In the development of battery technology, in addition to improvements in battery cell performance, safety issues have also become a problem that cannot be ignored. If the safety of a battery cell cannot be ensured, that battery cell cannot be used. Therefore, how to improve the safety of battery cells is a technical issue in battery technology that needs to be solved as soon as possible.

The present invention provides a battery cell, a manufacturing method and system for the same, a battery, and an electrical device that can enhance the safety of the battery cell.

In a first aspect, an embodiment of the present invention provides a battery cell comprising: a shell having a wall portion; an electrode component housed in the shell; a pressure release mechanism provided in the wall portion, the pressure release mechanism including a weak portion arranged to break and release pressure when the pressure inside the shell reaches a threshold value; a main body portion located within the area surrounded by the weak portion; and a connection portion located outside the weak portion for connecting the wall portion; wherein the main body portion protrudes in a direction away from the electrode component relative to the connection portion, and the pressure release mechanism has a first recess formed on the side facing the electrode component at a position corresponding to the main body portion.

In the battery cell provided in the embodiment of the present invention, in the above-described aspect, the main body protrudes away from the electrode component relative to the connection portion, causing a sudden change in cross section at the weak portion, resulting in stress concentration at the weak portion. Furthermore, the pressure release mechanism has a first recess formed on the side facing the electrode component at a position corresponding to the main body, which further promotes stress concentration at the weak portion, making the weak portion more susceptible to cracking. Therefore, when the pressure inside the shell reaches a threshold value, the pressure is released, ensuring the safety of the battery cell in the event of thermal runaway and advantageously improving the safety and stability of the battery cell in use.

In some embodiments, the weakened portion is formed by providing a recessed groove in the pressure release mechanism.

In the above-mentioned aspect, by providing a recessed groove, the thickness of a portion of the pressure release mechanism is reduced, forming a weak portion.

In some embodiments, both the main body portion and the connection portion are thicker than the weak portion.

In the above-described embodiment, the weak portion has less strength and is more easily broken than the main body portion and the connection portion, allowing pressure to be released from the battery cell in a timely manner.

In some embodiments, where the thickness of the connection portion is B1 and the thickness of the weak portion is W1, the relationship 0.1≦W1/B1≦0.5 holds.

In the above-mentioned aspect, when the thicknesses of the weak portions and connection portions are within the above numerical ranges, the processing precision of the weak portions can be improved and the uniformity of the thickness of the weak portions can be improved. Therefore, when the weak portions are subjected to alternating stress, the degree of destruction of the weak portions becomes uniform, and the consistency of battery rupture can be improved.

When W1/B1<0.1, the thickness of the weak part is relatively thin and the strength is low, making the weak part more susceptible to destruction when the battery cell is not experiencing thermal runaway. Furthermore, when forming weak parts of this thickness, there is significant variation in the size of the weak parts and poor uniformity in their thickness. Therefore, when the weak parts of different battery cells are subjected to alternating stresses, the areas or degrees of fatigue or aging may differ, resulting in poor consistency in the rupture or pressure release of different battery cells.

When W1/B1 > 0.5, the thickness of the weak part is relatively thick and the strength is high. Therefore, when the preset pressure value of the battery cell is small, the weak part is unlikely to break. Therefore, when the battery cell experiences thermal runaway, the gas inside the battery cell cannot be released in a timely manner, making the battery cell prone to expansion and ultimately causing an explosion.

In some embodiments, the groove and the first recess are positioned so that their projections in a first direction perpendicular to the thickness direction of the pressure release mechanism at least partially overlap.

In the above-described embodiment, the recessed groove and the weak portion are arranged in correspondence with each other in the thickness direction, and the recessed groove and the first recess are arranged so that their projections in the first direction at least partially overlap, thereby promoting stress concentration in the weak portion, making it easier for the weak portion to break, and enabling pressure release from the battery cell in a timely manner.

In some embodiments, the connection portion has a first outer surface and a first inner surface facing the electrode component in the thickness direction of the pressure release mechanism, and the groove is recessed relative to the first inner surface in a direction away from the electrode component and/or the groove is recessed relative to the first outer surface in a direction toward the electrode component.

In some embodiments, the connection portion has a first outer surface in the thickness direction of the pressure release mechanism and a first inner surface facing the electrode component, the first recess is recessed relative to the first inner surface in a direction away from the electrode component, and at least a portion of the main body portion protrudes from the first outer surface.

In some embodiments, when the thickness of the connection portion in the thickness direction of the pressure release mechanism is B1 and the height of the main body portion is H, H/B1≦2.

In the above-mentioned aspect, if the thicknesses of the connection portion and main body portion are within the above-mentioned numerical ranges, the height of the main body portion is appropriate, it is easy to process and mold, and stress concentration at weak portions is promoted, and interference between the main body portion and foreign objects outside the battery cell can be prevented.

If H/B1 > 2, the main body will be too high, making it difficult to process and mold, and a main body that is too high may protrude onto the surface of the battery cell and interfere with foreign objects outside the battery cell.

In some embodiments, the first recess has a bottom wall, the first recess extends from the first inner surface to the bottom wall in a direction away from the electrode component, and the bottom wall does not extend beyond the first outer surface in a direction away from the electrode component.

In the above-described embodiment, as the distance between the bottom wall and the first outer surface in the thickness direction decreases, the depth of the first recess in the thickness direction increases, making it easier for stress concentrations to form at the connection points between the main body portion corresponding to the position of the first recess and the weak portion, and making it easier for the weak portion to break.

In some embodiments, the pressure release mechanism further comprises a transition portion that is positioned around the connection portion to connect the wall portion and the connection portion, and that has a greater thickness than the connection portion.

In the above-mentioned aspect, the thickness of the transition portion is relatively thick, which increases the welding strength of the transition portion and prevents distortion, deformation, or melting during welding due to a small thickness of the transition portion. Furthermore, the thickness of the connection portion is relatively thin, so when the pressure release mechanism is subjected to alternating stress, it is less likely to crack and pressure can be released in a timely manner.

In some embodiments, if the thickness of the connection portion is B1 and the thickness of the transition portion is B2, then B1/B2≦2/3.

In the above-mentioned aspects, if the thickness of the connection and transition sections is within this numerical range, the thickness of the connection and transition sections is appropriate, and both the welding strength of the transition section and the strength requirements of the connection section can be met.

In some embodiments, the connection portion has a first outer surface in the thickness direction of the pressure release mechanism and a first inner surface facing the electrode component, and the transition portion has a second outer surface in the thickness direction of the pressure release mechanism and a second inner surface facing the electrode component, with the second outer surface protruding toward the first outer surface in the direction away from the electrode component and/or the second inner surface protruding toward the electrode component.

In some embodiments, the main body portion protrudes away from the electrode component relative to the transition portion.

In the above-described embodiment, a step structure is formed between the main body portion, the weak portion, the connection portion, and the transition portion, which makes it easy for stress to concentrate between the weak portion and the connection portion, particularly promoting stress concentration in the weak portion, making the weak portion more likely to break, and allowing the battery cell to release pressure in a timely manner.

In some embodiments, the connection portion has a minimum size in a first direction perpendicular to the thickness direction of the pressure release mechanism that is greater than 0.1 mm.

In the above-described embodiment, the weak portion is closer to the center of the pressure release mechanism, making the alternating stress experienced by the weak portion more uniform and increasing the likelihood of the weak portion cracking.

In some embodiments, the battery cell further includes a protective sheet attached to the outer surface of the wall portion and covering the pressure release mechanism.

In the above-described embodiment, the protective sheet can protect the pressure release mechanism and reduce distortion and sink marks that may occur in the pressure release mechanism due to an unexpected collision or damage to the pressure release mechanism by an external object.

In some embodiments, the shell includes an end cover and a housing, an opening is provided in the housing, the end cover is used to cover the opening, and the wall portion is the end cover.

In the above-described configuration, even if the pressure release mechanism is activated and releases high-temperature, high-pressure material, the structure of the end cover is not generally affected.

In a second aspect, the present invention provides a battery including a battery cell according to any one of the embodiments in the first aspect.

In a third aspect, the present invention provides an electrical device including a battery according to the embodiment of the second aspect. The battery is used to supply electrical energy.

In a fourth aspect, according to an embodiment of the present invention, a method for manufacturing a battery cell is provided, in which an end cover is provided with a pressure release mechanism and an electrode terminal, the pressure release mechanism including a weak portion, a main body portion located within an area surrounded by the weak portion, and a connection portion located outside the weak portion for connecting the end cover, the main body portion protruding from the connection portion, and the pressure release mechanism includes a first recess formed in a position corresponding to the main body portion, supplying an end cover, supplying an electrode component, supplying a housing having an opening, connecting the electrode component to the electrode terminal, and inserting the electrode component into the housing so as to seal the opening of the housing, and then connecting the end cover to the housing, wherein the weak portion is arranged to break and release pressure when the pressure inside the housing reaches a threshold value, the main body portion protruding from the connection portion in a direction away from the electrode component, and the pressure release mechanism includes a first recess formed on the side facing the electrode component in a position corresponding to the main body portion.

In a fifth aspect, according to an embodiment of the present invention, there is provided a battery cell manufacturing system comprising: a first supply device for supplying an end cover having a pressure release mechanism and an electrode terminal, wherein the pressure release mechanism includes a weak portion, a main body portion located within an area surrounded by the weak portion, and a connection portion located outside the weak portion for connecting the end cover, the main body portion protruding from the connection portion, and the pressure release mechanism having a first recess formed in a position corresponding to the main body portion; a second supply device for supplying electrode components; a third supply device for supplying a housing having an opening; a first assembly device for connecting the electrode components to the electrode terminals; and a second assembly device for inserting the electrode components into the housing so as to seal the opening of the housing and then connecting the end cover to the housing, the weak portion being arranged to break and release pressure when the pressure inside the housing reaches a threshold value; the main body portion protruding in a direction away from the electrode component relative to the connection portion, and the pressure release mechanism having a first recess formed on the side facing the electrode component at a position corresponding to the main body portion.

In order to more clearly explain the technical solutions relating to the embodiments of the present invention, the accompanying drawings used in the embodiments of the present invention will be briefly described below. However, the accompanying drawings described below are only some embodiments of the present invention, and it goes without saying that a person skilled in the art can derive other accompanying drawings based on the accompanying drawings without requiring any creative work.

1 is a structural schematic diagram of a vehicle according to an embodiment of the present invention; 1 is an exploded structural schematic diagram of a battery according to an embodiment of the present invention. FIG. 3 is a structural schematic diagram of the battery module shown in FIG. 2 . 1 is an exploded structural schematic diagram of a battery cell according to an embodiment of the present invention. 1 is a schematic cross-sectional view of a battery cell according to an embodiment of the present invention; FIG. 6 is an enlarged schematic view of A in FIG. 5 . FIG. 2 is an exploded structural schematic diagram of an end cover part of a battery cell according to one embodiment of the present invention. FIG. 2 is a schematic diagram of the top structure of a pressure release mechanism for a battery cell according to one embodiment of the present invention. FIG. 10 is a schematic diagram of the top structure of a pressure release mechanism for a battery cell according to another embodiment of the present invention. FIG. 10 is a schematic cross-sectional view taken along the line FF in FIG. 9. FIG. 11 is an enlarged schematic view of I in FIG. 10 . FIG. 10 is a partial cross-sectional schematic view of a pressure release mechanism for a battery cell provided in an alternative embodiment. FIG. 10 is a partial cross-sectional schematic view of a pressure release mechanism for a battery cell provided in another alternative embodiment. FIG. 10 is a partial cross-sectional schematic view of a pressure release mechanism for a battery cell provided in yet another alternative embodiment. 10 is a partial cross-sectional schematic view of a pressure release mechanism for a battery cell provided in yet another alternative embodiment. FIG. 1 is a flowchart of a method for manufacturing a battery cell according to one embodiment of the present invention. 1 is a schematic block diagram of a battery cell manufacturing system according to an embodiment of the present invention.

The accompanying drawings are not necessarily drawn to scale.

In order to clarify the objectives, technical solutions, and advantages of the embodiments of the present invention, the technical solutions of the embodiments of the present invention will be clearly described below with reference to the accompanying drawings of the embodiments of the present invention. It is clear that the following embodiments are not all embodiments, but only some of the embodiments of the present invention. Any other embodiments that can be obtained by those skilled in the art based on the embodiments of the present invention without requiring any creative work also fall within the scope of protection of the present invention.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention pertains. Furthermore, the terms used in the present specification are intended to describe the purpose of specific embodiments and are not intended to limit the present invention. The terms "comprise," "have," and any variations thereof in the specification, claims, and accompanying drawings are intended to cover non-exclusive inclusions. Terms such as "first," "second," and the like in the specification, claims, and accompanying drawings are intended to distinguish between different objects and are not intended to describe a specific order or hierarchy.

When referring to the present invention, the term "embodiment" means that a particular feature, structure, or characteristic described in combination with the embodiment may be included in at least one embodiment of the present invention. The appearance of the term in each location in the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment of other embodiments.

In describing the present invention, unless otherwise clearly specified or limited, the terms "attach," "connect," "join," and "attach" should be understood in a broad sense, and may refer to, for example, a fixed connection, a detachable connection, or an integral connection. It should also be noted that they may refer to a direct connection, an indirect connection via an intermediate medium, or internal communication between two elements. Those skilled in the art will understand the specific meanings of the above-mentioned terms in the present invention depending on the specific circumstances.

The term "and/or" in this invention merely describes the relationship between related objects and indicates that there are three relationships. For example, A and/or B means that A exists alone, A and B exist together, or B exists alone. Furthermore, the symbol "/" in this invention generally indicates that the related objects before and after it are in an "or" relationship.

In the embodiments of the present invention, the same reference numerals indicate the same elements, and for the sake of brevity, detailed descriptions of the same elements will be omitted in different embodiments. It will be understood that the thickness, length, width, and other dimensions of the various elements in the embodiments of the present invention shown in the drawings, as well as the thickness, length, width, and other dimensions of the entire integrated device, are merely illustrative and do not constitute any limitations on the present invention.

The term "plurality" as used herein means two or more (including two).

In the present invention, the battery cells may include lithium ion secondary batteries, lithium ion primary batteries, lithium-sulfur batteries, sodium lithium ion batteries, sodium ion batteries, magnesium ion batteries, etc., and are not limited to these in the embodiments of the present invention. The battery cells may be cylindrical, flat, rectangular, or have other shapes, and are not limited to these in the embodiments of the present invention. Battery cells are classified into cylindrical battery cells, rectangular prismatic battery cells, and soft-pack battery cells based on their packaging type, and are not limited to these in the embodiments of the present invention.

The battery referred to in the embodiments of the present invention is a single physical module containing one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in the present invention may include a battery module or a battery pack. A battery typically includes a case for packaging one or more battery cells. The case can prevent liquids or other foreign objects from affecting the charging or discharging of the battery cells.

A battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode sheet, a negative electrode sheet, and a separator. The battery cell operates primarily through the movement of metal ions between the positive and negative electrode sheets. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode current collector, and the current collector without the positive electrode active material layer protrudes onto the current collector with the positive electrode active material layer. The current collector without the positive electrode active material layer is stacked to form a positive electrode tab. For example, in a lithium-ion battery, the positive electrode current collector may be made of aluminum, and the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The current collector not coated with the negative electrode active material layer protrudes from the current collector coated with the negative electrode active material layer. The current collectors not coated with the negative electrode active material layer are stacked to form a negative electrode tab. The negative electrode current collector may be made of copper, and the negative electrode active material may be carbon or silicon. The separator may be made of PP (polypropylene) or PE (polyethylene). The electrode component may have a wound structure or a laminated structure, but the embodiment of the present invention is not limited to this.

The development of battery technology requires simultaneous consideration of many design factors, including performance parameters such as energy density, cycle life, discharge capacity, and charge/discharge rate, as well as battery safety.

The pressure release mechanism in a battery cell has a significant impact on battery safety. For example, if a short circuit or overcharging occurs, thermal runaway may occur inside the battery cell, causing a sudden rise in pressure or temperature. In such a situation, the pressure release mechanism can be activated to release the internal pressure and temperature to the outside, preventing the battery cell from exploding or catching fire.

A pressure release mechanism is an element or component that operates to release the internal pressure or temperature of a battery cell when the internal pressure or temperature reaches a preset threshold. The design of this threshold varies depending on design needs. The threshold may be determined by one or more materials from the positive electrode sheet, negative electrode sheet, electrolyte, and separator in the battery cell. The pressure release mechanism may specifically employ a pressure- or temperature-sensitive element or structure, such as an explosion-proof valve, gas valve, pressure release valve, or safety valve. That is, when the internal pressure or temperature of the battery cell reaches a preset threshold, the pressure release mechanism operates, or a weak structure in the pressure release mechanism breaks, creating an opening or passage for releasing the internal pressure or temperature.

The term "operation" as used herein refers to the pressure release mechanism being activated or in a certain state, thereby releasing the internal pressure and temperature of the battery cell. The operation of the pressure release mechanism includes, but is not limited to, cracking, fracturing, tearing, or releasing at least a portion of the pressure release mechanism. When the pressure release mechanism is activated, high-temperature, high-pressure materials inside the battery cell are expelled from the operating area as a release. In this way, the battery cell is depressurized and cooled so that the pressure or temperature can be controlled, preventing the occurrence of a potentially serious accident.

The emissions from battery cells referred to in this invention include, but are not limited to, electrolyte, dissolved or decomposed positive and negative electrode sheets, separator fragments, high-temperature and high-pressure gases produced by reactions, flames, etc.

After discovering the problem of battery cells not bursting and releasing pressure even when a preset thermal runaway condition is reached during a battery cell cycle, the applicant analyzed and researched the structure and operating environment of the battery cell. During transportation, temperature changes, or charging and discharging, the internal pressure of the battery cell may alternately rise and fall, causing the pressure release mechanism to open and close repeatedly. This means that the pressure release mechanism is subjected to alternating stresses caused by internal gas in the battery cell. The applicant discovered that when the preset pressure value of the battery cell is low, the strength required for the pressure release mechanism is low. However, to ensure the dimensional accuracy of the pressure release mechanism, it is necessary to maintain a certain strength. In this way, fatigue deformation and fracture are unlikely to occur even when subjected to alternating stresses caused by internal gas in the battery cell. Furthermore, even when the internal pressure of the battery cell exceeds the preset pressure value, the pressure release mechanism does not crack, preventing the battery cell from venting in a timely manner, posing a potential safety issue.

In light of the above problems discovered by the applicant, the applicant has improved the structure of the battery cell, and the technical solutions described in the embodiments of the present invention are applicable to battery cells, batteries including battery cells, and electrical devices that use batteries.

Electrical devices may include vehicles, mobile phones, portable equipment, laptops, boats, aircraft, electric toys, and power tools. Vehicles may be gasoline-powered vehicles, gas-powered vehicles, or new energy vehicles, and new energy vehicles may be pure electric vehicles, hybrid vehicles, or extended-range vehicles. Aircraft include airplanes, rockets, spaceplanes, and spaceships. Electric toys include stationary or portable electric toys, such as game consoles, electric car toys, electric boat toys, and electric plane toys. Power tools include metal-cutting power tools, polishing power tools, assembly power tools, and railway power tools, such as electric drills, electric grinding machines, electric wrenches, electric screwdrivers, electric hammers, electric impact drills, concrete vibrators, and electric planers. The embodiments of the present invention are not particularly limited to the above-mentioned electrical equipment.

For ease of explanation, the following embodiments will use a vehicle, which is an electrical device, as an example.

As shown in FIG. 1, a battery 10 is provided inside the vehicle 1. The battery 10 may be provided at the bottom, front, or rear of the vehicle 1. The battery 10 is used to supply electricity to the vehicle 1; for example, the battery 10 is used as an operational power source for the vehicle 1.

Vehicle 1 may further include a controller 1b and a motor 1a. Controller 1b controls battery 10 to supply electricity to motor 1a, and meets the operating electrical needs of vehicle 1, for example, for starting, navigating, and driving.

In some embodiments of the present invention, the battery 10 may not only serve as the operational power source for the vehicle 1, but may also serve as the drive power source for the vehicle 1, supplying drive power to the vehicle 1 in place of gasoline or natural gas, or in place of part of these.

As shown in Figures 2 and 3, the battery 10 includes a battery cell 30 (not shown in Figure 2). The battery 10 may further include a case for housing the battery cell 30.

The case is used to house the battery cells 30 and may be of various structural types.

In some embodiments, the case may include a bottom shell 11 and a top shell 12. The bottom shell 11 and the top shell 12 are fitted together. The bottom shell 11 and the top shell 12 collectively define a storage space for accommodating the battery cells 30. The bottom shell 11 and the top shell 12 may each have a hollow structure that is open on one side. When the open side of the bottom shell 11 is fitted to the open side of the top shell 12, a case having a storage space is formed. A seal may further be provided between the bottom shell 11 and the top shell 12 to achieve a sealed connection between the bottom shell 11 and the top shell 12.

In actual applications, the bottom shell 11 may be fitted to the ceiling of the top shell 12. The bottom shell 11 is also called the upper case, and the top shell 12 is also called the lower case.

The bottom shell 11 and the top shell 12 may have various shapes, such as a cylindrical body or a rectangular parallelepiped. In Figure 2, the bottom shell 11 and the top shell 12 are both rectangular parallelepiped structures, for example.

The battery 10 may have one or more battery cells 30. If there are multiple battery cells 30, the multiple battery cells 30 may be connected in series, parallel, or series-parallel. Series-parallel refers to the connection of multiple battery cells 30 either in series or in parallel. Multiple battery cells 30 may be connected directly in series, parallel, or series-parallel, and the entire battery cell set may be housed in a case. Alternatively, multiple battery cells 30 may be connected in series, parallel, or series-parallel in advance to form a battery module 20, and then the multiple battery modules 20 may be further connected together in series, parallel, or series-parallel and housed in a case.

In some embodiments, as shown in FIG. 3, the battery includes a plurality of battery cells 30. The plurality of battery cells 30 are pre-connected in series, parallel, or series-parallel to form a battery module 20. The plurality of battery modules 20 are then further connected together in series, parallel, or series-parallel and housed in a case.

In some embodiments, the multiple battery cells 30 in the battery module 20 are electrically connected by bus members to realize parallel, series, or series-parallel configurations of the multiple battery cells 30 in the battery module 20.

As shown in FIG. 4 , in some embodiments, the battery cell 30 includes a shell 40, an electrode component 50, an electrode terminal 60, an insulating member, and an adapter member 70. The shell 40 includes a housing 42 having an opening 421 and an end cover 41. The electrode component 50 is housed in the housing 42 and includes a tab 51. The end cover 41 is used to cover the opening 421. The electrode terminal 60 is attached to the end cover 41. The insulating member is located on the side of the end cover 41 facing the electrode component 50. The adapter member 70 is used to connect the electrode terminal 60 to the tab 51 so as to electrically connect the tab 51 to the electrode terminal 60.

In particular, the housing 42 may have various shapes, such as a cylinder or a rectangular parallelepiped. The shape of the housing 42 is determined according to the specific shape of the electrode component 50. For example, if the electrode component 50 has a cylindrical structure, the housing 42 may also have a cylindrical structure. If the electrode component 50 has a rectangular parallelepiped structure, the housing 42 may also have a rectangular parallelepiped structure. In Figure 4, both the housing 42 and the electrode component 50 have a rectangular parallelepiped structure, for example.

The housing 42 may be made of a variety of materials, including copper, iron, aluminum, stainless steel, aluminum alloys, and plastic, and the embodiments of the present invention are not particularly limited thereto.

The housing 42 may contain one or more electrode components 50. In Figure 4, the housing 42 contains two electrode components 50.

In some embodiments, the electrode component 50 further includes a positive electrode sheet, a negative electrode sheet, and a separator. The electrode component 50 may have a wound structure in which the positive electrode sheet, the separator, and the negative electrode sheet are formed by winding. The electrode component 50 may also have a laminated structure in which the positive electrode sheet, the separator, and the negative electrode sheet are stacked.

The positive electrode sheet may include a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode current collector. The negative electrode sheet may include a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. A separator is positioned between the positive electrode sheet and the negative electrode sheet to separate them so as to reduce the risk of short-circuiting between the positive electrode sheet and the negative electrode sheet.

In particular, the separator material may be PP (polypropylene) or PE (polyethylene).

The tabs 51 in the electrode component 50 are divided into positive and negative tabs. The positive tab may be the portion of the positive electrode current collector that is not coated with the positive electrode active material layer. The negative tab may be the portion of the negative electrode current collector that is not coated with the negative electrode active material layer.

In an embodiment of the present invention, as shown in Figures 4 and 5, the end cover 41 is used to cover the opening 421 of the housing 42 to form a sealed space for accommodating the electrode component 50, and the sealed space may be used to accommodate an electrolyte such as an electrolyte solution. The electrode terminal 60 is an output member for outputting electrical energy from the battery cell 30, and two electrode terminals 60 may be provided.

The housing 42 may have one or two openings 421. If the housing 42 has one opening 421, there may be one end cover 41. If the housing 42 has two openings 421, there may be two end covers 41. The two end covers 41 are fitted to cover the two openings 421, respectively, and each end cover 41 may be provided with an electrode terminal 60.

In some embodiments, as shown in FIG. 4, the housing 42 has one opening 421 and one end cover 41. The end cover 41 may be provided with two electrode terminals 60. One electrode terminal 60 is electrically connected to the positive tab of the electrode component 50 via one adapter member 70. The other electrode terminal 60 is electrically connected to the negative tab of the electrode component 50 via the other adapter member 70.

In some other embodiments, the housing 42 has two openings 421. The two openings 421 are provided on opposite sides of the housing 42, and there are two end covers 41. The two end covers 41 are fitted to the two openings 421 of the housing 42, respectively. In such a situation, each end cover 41 may have only one electrode terminal 60. The electrode terminal 60 of one end cover 41 is electrically connected to one tab (positive tab) of the electrode component 50 via one adapter member 70, and the electrode terminal 60 of the other end cover 41 is electrically connected to the other tab (negative tab) of the electrode component 50 via the other adapter member 70.

In some embodiments, as shown in FIG. 4, the battery cell 30 may further include a pressure release mechanism 80. The pressure release mechanism 80 is attached to the shell 40. The pressure release mechanism 80 is used to release pressure inside the battery cell 30 when the internal pressure or temperature of the battery cell 30 reaches a threshold.

For example, the pressure release mechanism 80 may be an explosion-proof valve, an explosion-proof sheet, a gas valve, a pressure release valve, or a safety valve.

Referring to Figures 4 through 7, in some embodiments, the shell 40 in embodiments of the present invention includes a wall portion having a through-hole 412 that is covered by the pressure release mechanism 80.

In an embodiment of the present invention, as shown in Figures 4 to 7, in order for the pressure release mechanism 80 to burst and release pressure in a timely manner, the embodiment of the present invention provides a battery cell 30 including a shell 40 having a wall portion, an electrode component 50 housed in the shell 40, a pressure release mechanism 80 provided in the wall portion, the pressure release mechanism 80 including a weak portion 83 arranged to burst and release pressure when the pressure inside the shell 40 reaches a threshold value, a main body portion 81 located within the area surrounded by the weak portion 83, and a connecting portion 82 located outside the weak portion 83 for connecting the wall portion, the main body portion 81 protruding in a direction away from the electrode component 50 relative to the connecting portion 82, and the pressure release mechanism 80 having a first recess 84 formed on the side facing the electrode component 50 at a position corresponding to the main body portion 81.

It should be noted that the electrode component 50 in this embodiment of the present invention may be a wound electrode component, a laminated electrode component, or any other electrode component.

In some embodiments, the electrode component 50 is a wound-type electrode component. The positive electrode sheet, negative electrode sheet, and separator all have a strip-like structure. In an embodiment of the present invention, the positive electrode sheet, separator, and negative electrode sheet may be stacked in order and wound two or more times to form the electrode component 50.

In some other embodiments, the electrode component 50 is a laminated electrode component. Specifically, the electrode component 50 includes multiple positive electrode sheets and multiple negative electrode sheets, and the positive electrode sheets and negative electrode sheets are alternately laminated in a direction parallel to the thickness direction of the positive electrode sheets and the thickness direction of the negative electrode sheets.

In embodiments of the present invention, the end cover 41 may include a wall portion, i.e., the pressure release mechanism 80 may be provided on the end cover 41, or the shell 40 may include a wall portion, i.e., the pressure release mechanism 80 may be provided on the shell 40. It is understood that the pressure release mechanism 80 in embodiments of the present invention is provided on the wall portion, and the shell 40 and the pressure release mechanism 80 may be separate structures, i.e., they may be processed and manufactured independently and then assembled by mechanical connection. The shell 40 and the pressure release mechanism 80 may also be integrally molded structures; for example, in the present invention, a predetermined area of the wall may be thinned to form the pressure release mechanism 80. For ease of explanation, the end cover 41 will be described as a wall portion in the embodiments described below.

The end cover 41 is thicker than the housing 42, making it more rigid. The end cover 41 is less likely to deform under the same pressure. The internal pressure of the battery cells 30 can alternate between high and low during transportation, temperature changes, or charging and discharging. Therefore, if a pressure release mechanism 80 is provided in the end cover 41, alternating stress acts on the pressure release mechanism 80, activating it and releasing high-temperature, high-pressure material, making it less likely to damage the structure of the end cover 41.

In the battery cell 30 according to the embodiment of the present invention, the weak portion 83 refers to a portion of the pressure release mechanism 80 that is weaker than the main body portion 81 and the connection portion 82 and is more susceptible to cracking, fracture, tearing, or opening. The pressure release mechanism 80 includes the weak portion 83, the main body portion 81, and the connection portion 82. The weak portion 83 is located at the connection between the main body portion 81 and the connection portion 82. It is understood that a predetermined region of the pressure release mechanism 80 is thinned, the thinned portion forms the weak portion 83, and the two portions separated by and connected by the weak portion 83 form the main body portion 81 and the connection portion 82. Alternatively, material processing is performed on a predetermined region of the pressure release mechanism 80, making that region weaker in strength than the other regions, with the weaker region forming the weak portion 83, and the two stronger portions separated by and connected by the weak portion 83 form the main body portion 81 and the connection portion 82.

The connection portion may be directly connected to the wall portion, or indirectly connected to the wall portion via another portion.

In some examples, the weakened portion may wrap around the body portion once. In other examples, the weakened portion may wrap around the body portion by a fixed angle, for example, the weakened portion may wrap around the body portion 180°-300°.

When the preset pressure value of the battery cell 30 is low, the strength required for the weak portion 83 is low. However, to ensure the dimensional accuracy of the weak portion 83, it is necessary to maintain a certain strength for the weak portion 83. During transportation, temperature changes, or charging/discharging of the battery cell 30, the internal pressure of the battery cell 30 may alternately increase and decrease. This may cause the pressure release mechanism 80 to bulge away from the electrode component 50 or to dent toward the electrode component 50. When the pressure release mechanism 80 alternates between bulging and denting, the weak portion 83 connected to the main body portion 81 and the connecting portion 82 is subjected to alternating stresses. Therefore, it is necessary to maintain a certain strength for the weak portion 83 to prevent the weak portion 83 from cracking due to the action of the alternating stresses. However, because the weak portion 83 has a certain strength, if the internal pressure of the battery cell 30 exceeds the preset pressure value, the weak portion 83 may not crack in a timely manner. If the internal pressure of the battery cell 30 is too high and the gas inside the battery cell 30 is not released in a timely manner, the battery cell 30 may expand and even explode.

In the battery cell 30 according to the embodiment of the present invention, the main body 81 protrudes away from the electrode component 50 relative to the connection component 82, causing a sudden change in cross section at the weak portion 83, resulting in stress concentration at the weak portion 83. Furthermore, the pressure release mechanism 80 has a first recess 84 formed on the side facing the electrode component 50 at a position corresponding to the main body 81, further promoting stress concentration at the weak portion 83 and making the weak portion 83 more susceptible to cracking. When the pressure inside the shell 40 reaches a threshold, the pressure is released, ensuring the safety of the battery cell 30 in the event of thermal runaway and advantageously improving the safety and stability of the battery cell 30 in use.

In some embodiments, the battery cell 30 further includes a protective sheet 90. The protective sheet 90 is attached to the outer surface of the wall of the shell 40 and covers the pressure release mechanism 80.

The protective sheet 90 can protect the pressure release mechanism 80 and reduce the possibility that an unexpected collision or damage to the pressure release mechanism 80 by an external object could cause the pressure release mechanism 80 to become distorted, deformed, or form a sink mark, which could further affect the weak part 83 of the pressure release mechanism 80 from breaking and bursting normally.

In some examples, a protective sheet 90 is positioned over the end cover and covers the through-holes 412. The material of the protective sheet 90 may be a plastic such as polyethylene or polypropylene.

In the battery cell 30 according to an embodiment of the present invention, the weak portion 83 may have a shape such as a curved structure or a ring structure. When the weak portion 83 has a curved structure or a ring structure, the main body portion 81 is located in the area surrounded by the weak portion 83, the connection portion 82 is located outside the weak portion 83, and the connection portion 82 is used to connect the wall portion of the shell 40.

In some embodiments, the weakened portion 83 may be formed by forming a notch, groove, or other structure in the pressure release mechanism 80 to reduce the strength of a portion of the pressure release mechanism 80.

In some embodiments, as shown in Figures 8 to 15, the weak portion 83 is formed by providing a recessed groove 83c in the pressure release mechanism 80. The connection portion 82 has a first outer surface 82a and a first inner surface 82b in the thickness direction X of the pressure release mechanism 80, with the first inner surface 82b facing the electrode component 50.

For example, the recessed grooves 83c may be formed by removing material from the pressure release mechanism 80 by machining, which is advantageous in reducing processing costs and difficulty. The weak portions 83 and the recessed grooves 83c are positioned in correspondence with each other in the thickness direction X.

In some embodiments, as shown in FIG. 8, the groove 83c in the pressure release mechanism 80 is curved, and the weak portion 83 corresponding to the groove 83c has a curved structure. Alternatively, the groove 83c in the pressure release mechanism 80 is linear, and the weak portion 83 corresponding to the groove 83c has a linear structure.

When the internal pressure of the battery cell 30 alternately fluctuates between high and low, the weak portion 83 is prone to fatigue aging and breakage, and the main body portion 81 reverses after the weak portion 83 breaks, thereby releasing the pressure from the battery cell 30.

In some embodiments, as shown in Figure 9, the recessed groove 83c in the pressure release mechanism 80 is annular. The weak portion 83 corresponding to the recessed groove 83c is also annular. The main body portion 81 is located in the area surrounded by the weak portion 83. The connecting portion 82 is used to connect the wall portions.

In some examples, the area surrounded by the groove 83c may be racetrack-shaped, circular, rectangular, or elliptical. If the internal pressure of the battery cell 30 alternately rises and falls, the weak portion 83 is prone to fatigue aging and breakage. If the weak portion 83 breaks, the through-hole 412 in the wall is exposed, allowing the battery cell 30 to communicate with the external environment and quickly release pressure.

In some embodiments, the groove 83c is recessed along the thickness direction X.

In some examples, as shown in Figures 10 and 11, the groove 83c is recessed relative to the first outer surface 82a in a direction toward the electrode component 50.

In some other examples, as shown in Figure 12, the groove 83c is recessed relative to the first inner surface 82b in a direction away from the electrode component 50.

In another example, as shown in Figure 13, there are two grooves 83c, one of which is recessed relative to the first inner surface 82b in a direction away from the electrode part 50, and the other groove 83c is recessed relative to the first outer surface 82a in a direction toward the electrode part 50.

In some embodiments, as shown in FIG. 14, both the main body portion 81 and the connection portion 82 are thicker than the weak portion 83. The weak portion 83 is weaker than the main body portion 81 and the connection portion 82 and is more easily broken, allowing pressure to be released from the battery cell 30 in a timely manner in the event of thermal runaway.

In some embodiments, where the thickness of the connection portion 82 is B1 and the thickness of the weak portion 83 is W1, the relationship 0.1≦W1/B1≦0.5 holds. When the thicknesses of the weak portion 83 and the connection portion 82 are within this range, the processing precision of the weak portion 83 can be improved, thereby improving the uniformity of the thickness of the weak portion 83. When the weak portion 83 is subjected to alternating stress, the degree to which the weak portion 83 is broken is uniform, thereby improving the consistency of battery rupture.

When W1/B1<0.1, the thickness of the weak portion 83 is relatively thin and the strength of the weak portion 83 is low, making the weak portion 83 susceptible to destruction when the battery cell 30 is not experiencing thermal runaway. Furthermore, when forming a weak portion 83 of this thickness, there is significant variation in the size of the weak portion 83 and poor uniformity in thickness. Therefore, when the weak portions 83 of different battery cells 30 are subjected to alternating stresses, there is a possibility that the areas or degrees of fatigue or aging will differ, resulting in poor consistency in the rupture or pressure release of different battery cells 30.

When W1/B1 > 0.5, the thickness of the weak portion 83 is relatively thick and the strength of the weak portion 83 is high. Therefore, when the preset pressure value of the battery cell 30 is small, the weak portion 83 is less likely to break. Therefore, when the battery cell 30 experiences thermal runaway, the gas inside the battery cell 30 cannot be released in a timely manner, and the battery cell 30 is more likely to expand, which may ultimately result in an explosion or other problem.

In the battery cell 30 according to the embodiment of the present invention, as shown in Figure 14, the first recess 84 is recessed relative to the first inner surface 82b in a direction away from the electrode component 50. Stress concentrations are formed in the weak portions 83, which are easily broken, allowing pressure to be released from the battery cell 30 in a timely manner.

In some embodiments, the groove 83c and the first recess 84 are positioned so that their projections in a first direction Y perpendicular to the thickness direction X of the pressure release mechanism 80 at least partially overlap. The groove 83c and the weak portion 83 are positioned correspondingly in the thickness direction X, and the groove 83c and the first recess 84 are positioned so that their projections in the first direction Y at least partially overlap, which promotes stress concentration in the weak portion 83 and makes it easier for the weak portion 83 to break, allowing pressure to be released from the battery cell 30 in a timely manner.

In some embodiments, as shown in FIG. 14, the first recess 84 is recessed relative to the first inner surface 82b in a direction away from the electrode component 50, and at least a portion of the main body 81 protrudes toward the first outer surface 82a. At least a portion of the main body 81 protrudes toward the first outer surface 82a, forming a stepped structure between the main body 81 and the connecting portion 82, significantly improving stress at the connection point between the main body 81 and the connecting portion 82. However, since the weak portion 83 is located at the connection point between the main body 81 and the connecting portion 82, stress concentration at the weak portion 83 is promoted.

In some embodiments, as shown in Figure 14, if the thickness of the connection portion 82 is B1 and the height of the main body portion 81 is H in the thickness direction X of the pressure release mechanism 80, then H/B1≦2. When the thicknesses of the connection portion 82 and the main body portion 81 are within the above numerical range, the height of the main body portion 81 is appropriate, it is easy to process and mold, and stress concentration at the weak portion 83 is promoted, preventing interference between the main body portion 81 and foreign objects outside the battery cell 30.

If H/B1 > 2, the height of the main body 81 will be too high, making it difficult to process, and a main body 81 that is too high may protrude from the surface of the battery cell 30 and interfere with foreign matter outside the battery cell 30.

In some embodiments, as shown in FIG. 14 , the first recess 84 has a bottom wall 841, and the first recess 84 is recessed from the first inner surface 82b to the bottom wall 841 in a direction away from the electrode component 50, and the bottom wall 841 does not extend beyond the first outer surface 82a in a direction away from the electrode component 50. As the distance between the bottom wall 841 and the first outer surface 82a in the thickness direction X decreases, the recession of the first recess 84 in the thickness direction X becomes deeper, making it easier for stress concentrations to form at the connection points between the main body portion 81 corresponding to the position of the first recess 84 and the weak portions 83, and making it easier for the weak portions 83 to break.

In some embodiments, the pressure release mechanism 80 of the present invention further includes a transitional portion 85. As shown in FIG. 14, the transitional portion 85 is installed around the connecting portion 82 to connect the wall portion and the connecting portion 82, and the transitional portion 85 is thicker than the connecting portion 82. The relatively thicker transitional portion 85 increases the welding strength of the transitional portion 85 and prevents distortion, deformation, or burn-through during welding due to a small thickness of the transitional portion 85. Furthermore, the relatively thin connecting portion 82 makes the pressure release mechanism 80 less likely to crack when subjected to alternating stress, allowing for timely pressure release.

In some embodiments, if the thickness of the connection portion 82 is B1 and the thickness of the transition portion 85 is B2, then B1/B2≦2/3. If the thicknesses of the connection portion 82 and the transition portion 85 are within this range, the thicknesses of the connection portion 82 and the transition portion 85 are appropriate, and both the weld strength of the transition portion 85 and the strength requirements of the connection portion 82 can be met.

It should be noted that the transition portion 85 has a second outer surface 85a and a second inner surface 85b in the thickness direction X of the pressure release mechanism 80, and that the second inner surface 85b faces the electrode component 50.

In some embodiments, the second outer surface 85a protrudes beyond the first outer surface 82a in a direction away from the electrode component 50.

In some embodiments, the second inner surface 85b protrudes beyond the first inner surface 82b in a direction toward the electrode component 50.

In some embodiments, the second outer surface 85a protrudes beyond the first outer surface 82a in a direction away from the electrode component 50, and the second inner surface 85b protrudes beyond the first inner surface 82b in a direction toward the electrode component 50.

For example, if the thickness of connection portion 82 is B1 and the thickness of transition portion 85 is B2, then B1/B2≦2/3. If the thicknesses of connection portion 82 and transition portion 85 are within this range, the thicknesses of connection portion 82 and transition portion 85 are appropriate, and both the welding strength of transition portion 85 and the tear strength of connection portion 82 can be met.

In some embodiments, the transition portion 85 and the connecting portion 82 are connected with a smooth transition, preventing the connection between the transition portion 85 and the connecting portion 82 from breaking during the installation process.

In some embodiments, as shown in FIG. 15 , the main body portion 81 protrudes away from the electrode component 50 relative to the transitional portion 85 in the thickness direction X. The transitional portion 85 is thicker than the connection portion 82. A stepped structure is formed between the main body portion 81, the weak portion 83, the connection portion 82, and the transitional portion 85, which tends to form stress concentrations between the weak portion 83 and the connection portion 82, particularly promoting stress concentration in the weak portion 83, making the weak portion 83 more likely to break, and allowing the battery cell 30 to release pressure in a timely manner.

In this embodiment of the present invention, the connection portion 82 has a minimum size in the first direction Y that is greater than 0.1 mm. The weak portion 83 is closer to the center position of the pressure release mechanism 80, making the alternating stress experienced by the weak portion 83 more uniform and increasing the likelihood of the weak portion 83 breaking.

As shown in Figure 16, an embodiment of the present invention is a method for manufacturing a battery cell 30,

An end cover 41 is provided with a pressure release mechanism 80 and an electrode terminal 60, the pressure release mechanism 80 including a weak portion 83, a main body portion 81 located in the area surrounded by the weak portion 83, and a connection portion 82 located outside the weak portion 83 for connecting the end cover 41, the main body portion 81 protruding from the connection portion 82, and the pressure release mechanism 80 including a first recess 84 formed in a position corresponding to the main body portion 81;

Providing electrode components 50;

Providing a housing 42 having an opening 421;

Connecting the electrode component 50 to the electrode terminal 60;

The method includes inserting the electrode component 50 into the housing 42 and then connecting the end cover 41 to the housing 42 so as to seal the opening 421 of the housing 42.

A method for manufacturing a battery cell (30) is provided in which the weak portion (83) is arranged to break and release pressure when the pressure inside the housing (42) reaches a threshold value, the main body (81) protrudes in a direction away from the electrode component (50) relative to the connection portion (82), and the pressure release mechanism (80) has a first recess (84) formed on the side facing the electrode component (50) at a position corresponding to the main body (81).

In a battery cell 30 manufactured using the battery cell 30 manufacturing method according to an embodiment of the present invention, the main body 81 of the pressure release mechanism 80 protrudes away from the electrode component 50 relative to the connection portion 82, causing stress concentration in the weak portion 83. Furthermore, the pressure release mechanism 80 has a first recess 84 formed on the side facing the electrode component 50 at a position corresponding to the main body 81, which promotes stress concentration in the weak portion 83, reducing the strength of the weak portion 83 and making it more susceptible to cracking. When the pressure inside the shell 40 reaches a threshold, the pressure is released, ensuring the safety of the battery cell 30 in the event of thermal runaway, and is advantageous in improving the safety and stability of battery use.

The battery cell 30 according to the embodiment of the present invention can be manufactured using the manufacturing method for the battery cell 30 according to the embodiment of the present invention.

As shown in FIG. 17, an embodiment of the present invention further includes a battery cell 30 manufacturing system 1000,

An end cover 41 provided with a pressure release mechanism 80 and an electrode terminal 60, the pressure release mechanism 80 including a weak portion 83, a main body portion 81 located in the area surrounded by the weak portion 83, and a connection portion 82 located outside the weak portion 83 for connecting the end cover 41, the main body portion 81 protruding from the connection portion 82, and the pressure release mechanism 80 having a first recess 84 formed in a position corresponding to the main body portion 81;

A second supply device 1002 for supplying electrode components 50;

A third supply device 1003 for supplying a housing 42 having an opening 421;

A first assembly device 1004 for connecting the electrode component 50 to the electrode terminal 60;

A second assembly device 1005 is provided for inserting the electrode component 50 into the housing 42 and then connecting the end cover 41 to the housing 42 so as to seal the opening 421 of the housing 42.

A manufacturing system (1000) for a battery cell (30) is provided, in which the weak portion (83) is arranged to break and release pressure when the pressure inside the housing (42) reaches a threshold value, the main body portion (81) protrudes in a direction away from the electrode component (50) relative to the connection portion (82), and the pressure release mechanism (80) has a first recess (84) formed on the side facing the electrode component (50) at a position corresponding to the main body portion (81).

In the battery cell 30 manufacturing system 1000 according to an embodiment of the present invention, the main body 81 of the pressure release mechanism 80 protrudes away from the electrode component 50 relative to the connection portion 82, causing stress concentration at the weak portion 83. Furthermore, the pressure release mechanism 80 has a first recess 84 formed on the side facing the electrode component 50 at a position corresponding to the main body 81. This promotes stress concentration at the weak portion 83, reducing the strength of the weak portion 83 and making it more susceptible to cracking. When the pressure inside the shell 40 reaches a threshold, the pressure is released, ensuring the safety of the battery cell 30 in the event of thermal runaway, and is advantageous in improving the safety and stability of battery use.

The battery cell 30 manufacturing system according to an embodiment of the present invention can carry out the battery cell 30 manufacturing method according to the above-described embodiment.

While the present invention has been described with reference to preferred embodiments, various modifications may be made and equivalent components may be substituted without departing from the scope of the present invention. In particular, the technical features described in each embodiment may be combined in any manner, provided there is no structural contradiction. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions encompassed within the scope of the claims.

X: Thickness direction Y: First direction 1: Vehicle 1a: Motor 1b: Controller 10: Battery 11: Bottom shell 12: Top shell 20: Battery 30: Battery cell 40: Shell 41: End cover 42: Housing 421: Opening 412: Through hole 50: Electrode part 51: Tab 60: Electrode terminal 70: Adapter member 80: Pressure release mechanism 81: Main body 82: Connection portion 82a: First outer surface 82b: First inner surface 83: Weak portion 83c: Groove 84: First recess 841: Bottom wall 85: Transition portion 85a: Second outer surface 85b: Second inner surface

Claims (16)

a shell having a wall;
an electrode component housed in the shell;
a pressure release mechanism provided in the wall portion, the pressure release mechanism including a weak portion arranged to be broken to release the pressure when the pressure inside the shell reaches a threshold value, a main body portion located within an area surrounded by the weak portion, and a connecting portion located outside the weak portion for connecting the wall portion;
Equipped with
the main body portion protrudes from the connection portion in a direction away from the electrode component,
the pressure release mechanism has a first recess formed at a position corresponding to the main body portion on a side facing the electrode component,
the weakened portion is formed by providing a recessed groove in the pressure release mechanism,
the thickness of each of the main body portion and the connection portion is greater than the thickness of the weak portion;
When the thickness of the connection portion is B1 and the thickness of the weak portion is W1, 0.1≦W1/B1≦0.5 is satisfied ,
In the thickness direction of the pressure release mechanism, when the thickness of the connection portion is B1 and the height of the main body portion is H, H/B1≦2.
Battery cell. the recessed groove and the first recess are provided so that projections thereof in a first direction perpendicular to the thickness direction of the pressure release mechanism at least partially overlap with each other.
The battery cell according to claim 1 . the connecting portion has a first outer surface and a first inner surface in a thickness direction of the pressure release mechanism, the first inner surface facing the electrode component;
the recessed groove is recessed relative to the first inner surface in a direction away from the electrode component and/or is recessed relative to the first outer surface in a direction toward the electrode component;
The battery cell according to claim 1 or 2. the connecting portion has a first outer surface and a first inner surface in a thickness direction of the pressure release mechanism, the first inner surface facing the electrode component;
the first recess is recessed relative to the first inner surface in a direction away from the electrode component;
At least a portion of the main body protrudes from the first outer surface.
The battery cell according to any one of claims 1 to 3. the first recess has a bottom wall, and the first recess is recessed from the first inner surface to the bottom wall in a direction away from the electrode component;
the bottom wall does not extend beyond the first outer surface in a direction away from the electrode component;
The battery cell according to claim 4 . the pressure release mechanism further includes a transition portion provided around the connection portion for connecting the wall portion and the connection portion, the transition portion having a thickness greater than that of the connection portion.
The battery cell according to any one of claims 1 to 5 . When the thickness of the connection portion is B1 and the thickness of the transition portion is B2, B1/B2≦2/3.
The battery cell according to claim 6 . the connecting portion has a first outer surface and a first inner surface in a thickness direction of the pressure release mechanism, the first inner surface facing the electrode component;
the transition portion has a second outer surface and a second inner surface in a thickness direction of the pressure release mechanism, the second inner surface facing the electrode component;
the second outer surface protrudes toward the first outer surface in a direction away from the electrode part, and/or the second inner surface protrudes toward the first inner surface in a direction toward the electrode part.
The battery cell according to claim 6 or 7 . the main body portion protrudes in a direction away from the electrode component relative to the transition portion;
The battery cell according to any one of claims 6 to 8 . a minimum size of the connecting portion in a first direction perpendicular to a thickness direction of the pressure release mechanism is greater than 0.1 mm;
The battery cell according to any one of claims 6 to 9 . The battery cell further includes a protective sheet attached to an outer surface of the wall portion and covering the pressure release mechanism.
The battery cell according to any one of claims 1 to 10 . The shell includes an end cover and a housing, the housing has an opening, and the end cover is used to cover the opening;
The wall portion is the end cover.
The battery cell according to any one of claims 1 to 11 . A battery comprising the battery cell according to any one of claims 1 to 12 . 14. An electrical device comprising the battery of claim 13 for supplying electrical energy. supplying an end cover, the end cover being provided with a pressure release mechanism and an electrode terminal, the pressure release mechanism including a weak portion, a main body portion located within an area surrounded by the weak portion, and a connection portion located outside the weak portion for connecting the end cover, the main body portion protruding from the connection portion, and the pressure release mechanism having a first recess formed at a position corresponding to the main body portion;
Providing an electrode component;
providing an enclosure having an opening;
connecting the electrode component to the electrode terminal;
inserting the electrode component into the housing and then connecting the end cover to the housing so as to close the opening of the housing;
Including,
the weakened portion is arranged to break and release pressure when a pressure inside the housing reaches a threshold;
the main body portion protrudes from the connection portion in a direction away from the electrode component,
the pressure release mechanism has the first recess formed at a position corresponding to the main body portion on a side facing the electrode component,
the weakened portion is formed by providing a recessed groove in the pressure release mechanism,
the thickness of each of the main body portion and the connection portion is greater than the thickness of the weak portion;
When the thickness of the connection portion is B1 and the thickness of the weak portion is W1, 0.1≦W1/B1≦0.5 is satisfied ,
In the thickness direction of the pressure release mechanism, when the thickness of the connection portion is B1 and the height of the main body portion is H, H/B1≦2.
Battery cell manufacturing method. a first supply device for supplying an end cover, the end cover being provided with a pressure release mechanism and an electrode terminal, the pressure release mechanism including a weak portion, a main body portion located within an area surrounded by the weak portion, and a connection portion located outside the weak portion for connecting the end cover, the main body portion protruding from the connection portion, and the pressure release mechanism having a first recess formed at a position corresponding to the main body portion;
a second supply device for supplying the electrode component;
a third supply device for supplying an enclosure having an opening;
a first assembly device for connecting the electrode component to the electrode terminal;
a second assembly device for inserting the electrode component into the housing and then connecting the end cover to the housing so as to close the opening of the housing;
Equipped with
the weakened portion is arranged to break and release pressure when a pressure inside the housing reaches a threshold;
the main body portion protrudes from the connection portion in a direction away from the electrode component,
the pressure release mechanism has the first recess formed at a position corresponding to the main body portion on a side facing the electrode component,
the weakened portion is formed by providing a recessed groove in the pressure release mechanism,
the thickness of each of the main body portion and the connection portion is greater than the thickness of the weak portion;
When the thickness of the connection portion is B1 and the thickness of the weak portion is W1, 0.1≦W1/B1≦0.5 is satisfied ,
In the thickness direction of the pressure release mechanism, when the thickness of the connection portion is B1 and the height of the main body portion is H, H/B1≦2.
Battery cell manufacturing system.